Low Back Pain

Red flags, imaging stewardship & stepped care

Field: Pain & MSKCode: PA-02Updated: June 2026Reference: RACGP / Choosing Wisely AU

Around 90% of low back pain resolves within 6 weeks. Image only if a red flag is present or conservative treatment fails beyond 6 weeks — degenerative changes and disc bulges are common incidental findings even in people without pain. Encourage normal activity: bed rest worsens outcomes.

Red flags — ask in every consult

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Cancer — age >50 with new pain, history of cancer, unexplained weight loss, night pain, no relief with rest.

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Infection — fever, immunosuppression, IV drug use, or recent spinal surgery/procedure.

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Fracture — significant trauma, or minor trauma with osteoporosis, long-term steroid use, or age >70.

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Cauda equina (emergency) — saddle anaesthesia, bilateral leg symptoms, new bladder or bowel dysfunction.

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Inflammatory — age <40, morning stiffness >30 min, improves with exercise, alternating buttock pain.

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Progressive neurology — worsening or severe leg weakness, or bilateral neurological signs.

Classify the pain (red flags excluded)

Non-specific (~90%) — no red flags or neurological signs; axial pain ± thigh referral — reassure and keep moving.

Radicular/sciatica — dermatomal leg pain often worse than back pain; positive straight-leg raise; motor, sensory or reflex change.

Claudication — bilateral leg symptoms worse on standing/walking, eased by flexion — suggests spinal stenosis.

Yellow flags — fear-avoidance, catastrophising, a compensation claim — predicts chronicity, address early.

Imaging stewardship

X-ray: suspected fracture or inflammatory change at the SI joints; not for routine non-specific LBP.
MRI: persistent radicular pain beyond 6 weeks, a red flag, or surgical planning; not first-line for non-specific LBP.
CT: bony detail when MRI is contraindicated, or fracture assessment; not for routine screening.
Bone scan: suspected metastases, osteomyelitis or an occult fracture; not for non-specific LBP.

Stepped care — most recover at 1–2

1. Education & reassurance: most LBP is benign, movement is safe, typical recovery 4–6 weeks.
2. Movement & exercise: stay active, graded exercise, physiotherapy where available.
3. Simple analgesics (if persisting beyond ~6 weeks): short-course oral NSAID if no contraindication, paracetamol PRN.
4. Referral & imaging (if persisting): physiotherapy review, MRI if radicular, pain clinic.

Allied health & MBS planning — Up to 5 Medicare-subsidised allied health visits per calendar year are available under a GP Chronic Condition Management Plan (replacing the former EPC arrangements). Confirm current item numbers and eligibility at mbsonline.gov.au.

Safety

Ask the red-flag questions at every LBP consultation, not only at first presentation.
Don't image routine non-specific LBP — degenerative changes and disc bulges are common incidental findings and rarely change management.
Avoid bed rest and avoid opioids for LBP — marginal benefit, real harm; encourage normal activity instead.

Red flags / refer

Cauda equina syndrome, a progressive neurological deficit, or suspected fracture/spinal infection/malignancy → emergency department, same day.
Radicular pain with a neurological deficit, or failed conservative treatment beyond 6–12 weeks with imaging confirming a surgical target → spinal surgery.
Chronic LBP beyond 3 months, multiple failed interventions, or a significant psychosocial component → pain clinic.

PA-02 v1.0 · Reviewed Jun 2026 · Review Jun 2027

For health-professional use. Framework: RACGP Low Back Pain Guideline, Choosing Wisely Australia. Image only if red flags or management will change. Confirm current MBS item numbers at mbsonline.gov.au.